Explanation:

Correct option 1: 108

Calculation:
Let the 1st no. be 'x' and 2nd no. be 'y' then
=> x=3y
According to the question,
72 = (x+y) / 2

or

72 = (3y+y) / 2

Solving we get
=>y = 36
Since, x = 3y then
⇒x=3 x 36 = 108
The first number is 108.